Method of and apparatus for proportioning liquids



- Aug. 22, 1944. G. M. TIMPSON 2,356,286

METHOD OF AND APPARATUS FOR PROPORTIONING LIQUIDS Filed Sept. 15, 1942 2Sheets-Shet 1 r INVENTOR LEW/S 6. Mom/5 T/MP50/v BY iATQRNEY 7 Aug. 22,1944. L. G. M. TlMPSON METHOD OF AND APPARATUS FOR PROPORTIONING LIQUIDSFiled Sept. 15, 1942 2 SheetsSheet 2 ATTORNEY m mm MW m R .1 0

Patented Aug. 22, 1944 I UNITED STATES PATENT orrica METHOD OFANDAPPARATUSFOR'PROPOB- TION-ING- LIQUIDS Lewis G. Morris: Timpson,Pl'ainfleld, N. 1;, assignor to: Pyrene-Mlnimax Corporation, Newark, N.1.. a corporation of Delaware Application September 15, 1942, Serial No.458,437

13 Claims. (CL 299-83) This invention relates to a method paratus forbringing together or intermingling in correct proportions two liquidsfrom separate sources, under pressure, and for delivering the mixture ofthe two liquids'under pressure to a point of use. It relatesparticularly to the introduction of a foam stabilizing solution indesired proportions into a stream of water, the mixture to be used inthe production of fire extinguishing foam by the subsequentincorporation'therein of air or other gas. I

Many problems are presented in attempting to produce a substantiallyuniform mixture of water and foam stabilizing solution for deliveryunder high pressure to suita ble foam-producing equipment which in turnis capable of delivering the foam under pressure to the seat of a'fire.The available line pressure in the water mains at a certain point issubject to considerable fluctuation and the volume of water utilized inany given period likewise varies widely. Thus, it frequently happensthat additional hose lines and play pipes connected with a particularmain are put into use in the course of fighting a fire, or certain linesmay be cut out of use, with resultant changes in available pressure. 80also, the discharge nozzle for a particular play pipe may be adjusted inthe course of use to vary the volume of water or foam being dischargedthrough it. It is difllcult, under these conditions, to insure theintroduction into the water of just the right amount of foam stabilizerat all times.

For most efllcient and effective use of a foam stabilizing solution, itis important to maintain a predetermined proportioning of'it to thewater into which it is introduced. Regular, commercial of and apfoamstabilizing solutions should ordinarily be added to the extent of about5% of the water, by volume. If a greater proportion is added, there isunnecessary. wastage of the stabilizer, while if less is added, a goodstable foam is not likely to be produced. Some small variation in theexact proportions used is, of course. permissible without serious harmbut the departure from the optimum percentage of foam stabilizer, shouldnot be great.

Heretofore various schemes or arrangements have been suggested forinsuring the correct, pr0- portioning of foam stabilizer to water butthese have all been subject to various limitations. Some have beenrestricted to batch operations of relatively small units. relying uponwater and foam stabilizer stored in tanks; others relying upon waterunder line. pressure have utilized an and r Fig. 3 is an. enlarged crosssectional view the mixture any substantial distance to the seat of thefire. Certain of the priorschemes have required location .of the pumpingor other pressure-creating means in the neighborhood of the fire whileothers have required a reservoir for the foam solution in closeproximity to the nozzle in which the mixture is produced. Various otherlimitations have also existed vin proportioning schemes previouslysuggested.

A primary object of the present invention has been to provide a simplebut effective method and means for insuring the proper proportioning offoam stabilizer to water in a fire foam producing system in whichthewater and stabilizer are both available under substantial pressureand in which the proportioning and mixing may take place at anyconvenient point, remote from the sources of both the water andstabilizing solution and from the point of use of the mixture. Thearrangement is such that a substantially uniform mixture may bemaintained with a minimum of effort and without requiring any specialexperience or the exercise of any great amount of care or thought. Thisis .of considerable importance Other objects and advantages of theinvention will appear from a detailed description of an i1- lustrativeform of the same which will now be given in conjunction with theaccompanying drawings, in which:

Fig. 1 is a plan view of a portable proportioning unit constructed andadapted to be used in accordance with the invention; 4 Fig. 2 is an endelevation of the improved unit,

through the mainconduit of the unit, taken along the line 3-3 of Fig. 2.V

The improved proportioner unit is adapted for insertion at anyconvenient point ina pipe-line or hose-line forming part of the fireextinguishing system. for any n property or locality. The

excessive amount of the pressure to bring about inlet side of the unitmay be connected, for example, with one section of a pipe or hose-line lextending from a hydrant or any suitable outlet from a water-main. Tothe discharge side of the unit there may be connected another section llof pipe or hose which is adapted to deliver the mixture of water andfoam stabilizer, produced within the unit, to the point of use of thefoam. At the discharge end of the hose-line H there may suitably beprovided a nozzle construction of any of the types illustrated in mypending application Ser. No. 417,220, filed on October 31, 1941, or inmy prior Patents No. 2,057,218, granted October 13, 1936, and No.2,146,605, granted February '7, 1939. Any other suitable means may beemployed for introducing the air or other gas into the mixture of waterand foam stabilizer to produce the desired foam. I To insert theimproved proportioning unit in the hose-line I0, I I, it is simplynecessary to uncouple the two sections 10 and H of the hose and toinsert the unit between the free ends of the sections. It will beunderstood that for the protection of a large area, such as thatoccupied by an oil refinery, a number of pipe-lines or hoselines l0, llmay extend from the same watermain or hydrant to a plurality ofdifferent points and each of these lines may have inserted between twoof its sections one 'of the improved units.

Turning now to the construction of the unit, it may suitably be providedwith a base i2, preferably in the form of a wood block of appropriatedimensions and having at its opposite ends a pair of handles Band [4.Each handle may simply be formed of sections of pipe connected togetherby elbows, as indicated, to form a U-shaped mem ber. The free ends ofthe U-shaped member may be passed through suitable holes formed in thewood block and they may be threaded to receive screw-threaded, retainingcaps l5. The latter are preferably so formed as to provide spikes orprojections adapted for engagement with cinders or soft earth to insurethe stability of the unit during operation. Above the-upper surface ofthe block i 2 each branch of the U-shaped handle may be provided with aflange or projection i8 suitably secured to the pipe. The block may beclamped between these flanges and the cap members l5.

other devices mounted on the block so as to facilitate their use and atthe same time afford protection for the other devices which will bedescribed.

Adjacent one end of the block I2 there is 'secured a transverselyextending block H which carries a pair of straps l8 for holding down theconduit means adapted to be inserted between the hose sections l0 andII. This conduit means may suitably comprise a union having a couplingelement I8 adapted to be connected with the threaded end of the hosesection 10. A nipple 20 of reduced diameter, forming part of the union,is connected with an expansion coupling 2 I. The large end of theexpansion coupling is connected by a nipple or pipe section 22 with areducing coupling 23, which is in turn connected with one end of aVenturi tube 24. At that end'of the latter connected with the coupling23, the inner surface 25 is tapered inwardly to form an extension of theinner surface of the coupling and to gradually reduce the interiordiameter of the conduit to the desired extent at the throat portion 28of the Venturi tube. Beyond this throat section the inner wall 21 of thetube is flared outwardly along a gradual taper, as indicated in Fig.

As indicated in Fig. 2, the handles 1 preferably extend upwardly to apoint abov the 3. The opposite end of the Venturi tube is connected withan expansion coupling 28, which is in turn connected with the smallerend 29 of a male expansion coupling. At its larger end 30 this malecoupling is adapted to receive the coupling element of the hose I I.

In the region of the throat 28 of the Venturi tube the latter isprovided with an enlarged flange or projection 3| having a threadedrecess 32, in its outer surface, connected through a small passageway32a with the interior of the tube and adapted to receive a small nipple33. The latter is connected with an elbow 34 and a small pipe section 35with a T-member 38. One of the branches of the latter is connected by anelbow 31 and fittings 38 with a check valve 39. The opposite side of thelatter is connected by a nipple or pipe section 40 and a union 4| with asuitable source of supply of the foam stabilizer. A pedestal clamp 40a,surrounding the nipple 40, serves to retain the latter and th adjoiningparts in proper position on the base. The stabilizer solution is adaptedto be delivered, to the connections indicated, under pressure which issubject to reg ulation or variation at will. This may be accomplished bycontrol of a suitable pump or by the regulation or adjustment of apressure-reducing valve 42 connected by means of nipples 43 with theunion 4| and with a hose 44 through which the foam stabilizer solutionis delivered from its source of supply.

The other branch of the T-member 38 is connected by a line 48 with oneside of a duplex pressure gauge 48. This gauge may be of any suitable,known construction which'is suchthat two separate pressures may beindicated by two separate hands 41 and 48. The pressure at the T 36 may,for example, be indicated by the hand 41 while the pressure in the largediameter section 22 of the conduit may be indicated by the hand 48. Forthis purpose, the second pressureresponsive element of the gauge may beconnected by a line 49 with a threaded opening 50 through the wall ofthe section 22.

In the normal operation of the apparatus, water from the main or a firehydrant is allowed to flow continuously through the conduit insertedbetween the sections In and II of the hose. This water may, for example,be under a pressure of 100 lbs/sq. in. at the section 22. However, dueto the increased velocity at the throat of the Venturi tube duringoperation of the equipment, the pressure at this point will be reducedto an extent depending upon the rate of flow. If the flow is at the rateof 100 gallons per minute, the pressure differential between the twopoints will be about 15 lbs/sq. in. Now, if the pressure of the foamstabilizer at the T 36 is so maintained, by regulation of the valve 42or the like, as to substantially equal the pressure in the section 22,it will be clear that under the conditions mentioned a 15-lb.differential will exist for the introduction of the foam stabilizerthrough the restricted passage 32a. By appropriate correlation of theinterior diameters of the section 22, throat 26, and passage 32a,correct proportioning of the foam stabilizer to the water may bemaintained, under substantially all conditions, likely to be encounteredin the operation of a given unit, by simply keeping the indicator hands41 and 48 of the gauge 48 in approximate coincidence. Thus, an attendantmay simply observe the gauge and then regulate the pressure of the foamstabilizer, by adjustment of the valve 42 or the like, to follow thefluctuations in pressure in the section 22. No reference to a chart isnecessary to determine what pressure should be maintained on the foamstabilizer to correspond with a given water pressure and rate of flow.

Assuming that the volume of water flowing through the conduit remainssubstantially the same throughout minor fluctuation of the pressure inthe section 22, there will be maintained substantially the samedifferential between the pressure at the throat 26 and the pressure ofthe foam stabilizer at the T 36. However, if any substantial change inthe volume of flow occurs, either as a result of a change in thepressure of the water in the section 22 or due to manipulation of theplay nozzle at the end of the hose-line H,

, this variation in flow will be immediately reflected in the pressuredifferential between the section 22 and throat 26. The relation betweenfiow and pressure differential is indicated by the following data: Ithas been found that for a pressure of 100 lbs/sq. in. in the section 22,there will be a pressure of 90 lbs/sq; in. at the throat 26 if only 60gals. per min. are passing through the conduit. The pressure at thethroat 26 will drop to about 85 lbs./sq. in. when the rate of flowisincreased to 100 gals. per min. and it will drop to about 80 lbs/sq.in. when the rate of flow is 140 gals, per min. and to about 75 lbs/sq,in. when the flow is at the rate of 180 gals. per min. It will be seen,therefore, that as the volume of flow increases, the pressuredifferential under which the foam stabilizer will be introducedcorrespondingly increases so as to maintain substantially constantproportioning of thestabilizer to water. If the pressure in the mainshould vary substantially while the volume of flow remains the same,there would be a change in the pressure drop at the throat 26, i. e. forhigher pressures the drop would begreater. But in normal operation, anychange in the water pressure in the main will result in a correspondingchange in the volume of flow and, therefore, correct proportioning willbe maintained.

It will be understood that each unit constructed in accordance with theinvention will be so di-.

mensioned,' particularly with respect to the interior diameters of thesection 22, throat 26 and passage 3211 as to insure the introduction ofthe correct amount of foam stabilizer at a particular normal waterpressure. Assuming that it is desired to introduce of foam stabilizersolution into the water, the dimensions indicated will have one relationwhen the normal water-line pressure is 100 lbs/sq. in. and will haveanother relation when the normal water-line pressure is, say, '75lbs/sq. in. or 150 lbs/sq. in. Within reasonable limits ofvariationfror'n the normal pressure, only slight deviation from thecorrect proportioning will result from the operation of a particularunit.

As a typical example, it has been found that for a water-line pressureof about 100 lbs. /sq. in., the interior diameter of the section 22should be about 2 while the diameter of the throat 26 should be about 7and the diameterof the passage 32a should be about Thus, the throat hasbetween one-eighth and one-ninth the cross-sectional area of section lzwhile passage 320. has about one-tenth the cross-sectional area of thethroat 26. V

The provision of a large increase in velocity of flow through the throat26, by having this less than one-fifth and preferably about one-eighththe cross-sectional area of the section 22, insures a substantialpressure drop at the throat and hence a relatively high head for theintroduction of the foam stabilizer. This allows for a substantial,sudden variation in the water-line pres sure without danger of causing areverse flow of water through the passage 32a into the foam stabilizerline. However, if the water-pressure should suddenly increase to a pointat which such reverse flow would occur, the check valve 39 would operateto prevent the flow of the water into the foam stabilizer line 44.

It is not essential that a Venturi construction be employed in-theconduit inserted between the hose-lines Ill and II. If desired, anabrupt change in dimension, or a series of shoulders, might be providedat some point between the section 22 and the passage 26 at which thefoam stabilizer is introduced. It is primarily important to provide asubstantial difference in the velocity of flow at these two points, asabove indicated; However, the Venturi construction'illustrated in Fig. 3is the preferred way of accomplishing the result since it does so withthe highest efllciency. There is, naturally, some loss in pressurebetween the inlet and outlet ends of the complete conduit but with theVenturi construction illustrated, the loss in pressure from the hosesection 10 to the hose section II is not more than about 5%. Withothertypes of construction a substantially greater loss may beencountered. v

While an illustrative form of the invention has been described inconsiderable detail, it will be understood that numerous changes may bemade in the construction and arrangement of the various parts of theapparatus and in the mode of operating the same without departing fromthe general principles and scope of the invention.

I claim:

1. A method of introducing a predetermined proportion of foam stabilizerunder variable pressure intoa flowing stream of water under pressurewhich comprises causing the water to flow at greatly increased velocitythrough a limited space, introducing foam stabilizer under pressure Iinto the waterwithin said limited space, and adjusting the pressure ofthe foam stabilizer to maintain the same substantially equal to that ofthe water in advance of said limited space.

2. A method of introducing a predetermined proportion of foam stabilizerunder variable pres sure into a flowing stream of water underpressurewhich comprises causing the water to flow at a relatively lowvelocity through one zone and Y a relatively high. velocity throughanother zone, introducing foam stabilizer under pressure into the waterin the high velocity zone, determining the pressure ofthe water in thelow velocity zone and'of the stabilizer at a point in advance of itsintroduction into the water, and maintaining said pressuressubstantially equal. V

3. In apparatus of the class described a conduit having a portion ofreduced cross-sectional area intermediate its ends, means forintroducing'a liquid into said conduit at one end, means for introducinga second liquid into said conduit at said portion of reducedcross-section, and

manually adjustable means for varying the pressure of said second liquidadjacent its point of introduction into said portion of reducedcrosssection. V

4. In apparatus of the class described a conduit having a portion ofreduced cross-sectional area intermediate its ends, means for introducing a liquid into said conduit at one end, means for introducing asecond liquid into said conduit at said portion of reducedcross-section, means for separately indicating the pressures of the twoliquids at points adjacent but slightly removed from said portion ofreduced cross-sectional area, and manually adjustable means for varyingthe pressure of said second liquid adjacent its point "of introductioninto said portion 01 reduced cross-section.

5. In apparatus of the class described a conduit having a Venturisection intermediate its ends, means for introducing a liquid into saidconduit at one end, means for introducing a second liquid into saidconduit at the throat of said Ventrui section, and manually adjustablemeans for varying the pressure of said second liquid adiacent its pointof introduction into the throat of said Venturi section.

6. A portable unit for proportioning two liq-- uids brought togetherunder pressure which comprises a conduit having a section of relativelysmall cross-sectional area and a section of substantially greatercross-sectional area, means for connecting said conduit into a linecarrying one of said liquids under pressure, means for delivering theother of said liquids under pressure and introducing the same into saidconduit at said section of relatively small cross-sectional area, mean-sfor regulating the pressure of said other liquid, and pressure gaugingmeans for indicating the pressure of said one liquid at said section ofgreater cross-sectional area and for indicating the pressure or saidother liquid at a point adjacent its point of introduction into saidconduit.

'7. A portable unit for proportioning two liquids brought together underpressure which comprises a conduit having a section of relatively smallcross-sectional area and a section of sub-' stantially greatercross-sectional area, means for connecting said conduit into a linecarrying one of said liquids under pressure, means for delivering theother of said liquids under pressure and introducing the same into saidconduit at said section of relatively small cross-sectional area, meansfor regulating the pressure of said other liquid, and pressure gaugingmeans having'a plurality of juxtaposed indicators for indicating thepressure of said one liquid at said section 01' greater cross-sectionalarea and for indicating the pressure or said other liquid at a pointadjacent its point of introduction into said conduit.

8. A portable unit for proportioning two liquids brought together underpressure which comprises a conduit having a portion of Venturi form,means for connecting said conduit into a line carrying one of saidliquids under pressure, means for delivering the other of said liquidsunder pressure and introducing the same into said conduit at the throatof said portion of Venturi form, means for regulating the pressure ofsaid other liquid, and pressure gauging means for indicating thepressure ofsaid one liquid at the point of greatest diameter of saidportion of Venturi form and for indicating the pressure of said otherliquid at a point adjacent its point of introduction into said conduit.

9. A portable unit for introducing a foam stabilizing solution indesired proportion into a stream of water under pressure for the purposeof introducing fire extinguishing foam whichcomprises, a base, a conduitmounted on, said base and having a section of relatively smallcrosssectional area and a section having a cross-sectional area at leastfive times as great as that of the first mentioned section, means forconnecting said conduit into a high pressure water line, means fordelivering a foam stabilizing solution under pressure and introducingthe same into said conduit at said section of relatively smallcross-sectional area, means for regulating the pressure of saidsolution, and means on said base for indicating in juxtaposed relationthe pressure of the water at said section of relatively largecross-section and the pressure of said solution at a point adjacent itspoint oi introduction into said conduit.

10. A portable unit for introducing a foam stabilizing solution indesired proportion into a stream of water under pressure for the purposeof producing fire extinguishing foam which cornprises, a base, a conduitmounted on said base and having a section of relatively smallcross-sectional area and a section having a cross-sectional area atleast five times as great as that of the first mentioned section, mensfor connecting said conduit into a high pressure water line, means fordelivering a foam stabilizing solution under pressure and introducingthe same into said conduit at said section of relatively smallcross-sectional area, said delivery means including a restricted passagehaving less than one-fifth the cross-sectional area of said section ofrelatively small area, means for regulating the pressure of saidsolution, and means on said base for indicating in juxtaposed relationthe pressure of the water at said section of relatively large crosssection and the pressure or said solution at a point adjacent its point01 introduction into said conduit.

11. A method of utilizing a conduit having a portion of relatively largecross-section and a following portion of reduced cross-section forbringing together two liquids under independent pressure inpredetermined proportions which comprises flowing one or the liquidsfirst through said portion of relatively large cross-section stcomparatively low velocity and high pressure and then through saidportion or reduced cross-section at higher velocity and lower pressure,in-

troducing the other of said liquids into said eonduit at said portion ofreduced cross-section, and varying the pressure of said other liquidadjacent its point of introduction to substantially coincide with thepressure of said one of the liquids in said portion of relatively largecrosssection in advance or said portion of reduced cross-section;

12. A. method of utilizing a conduit having a portion of relativelylarge cross-section, and a following portion of reduced cross-sectionfor bringing together two liquids under independent pressure inpredetermined proportions which comprises flowing one of the liquidsfirst through said portion of relatively large cross-section'atcomparatively low velocity and high pressure and then through saidportion of reduced cross-section at higher velocity and lower pressure,introducing the other of said liquids into said conduit at said portionof reduced cross-section, restricting the flow of said other of saidliquids in accordance with the desired proportioning o! assesses E5bringing together two liquids under independent pressure inpredetermined proportions, the conduit having an Orifice leading intothe same at said portion of reduced cross-section whose area in relationto the area or said reduced crosssection is greater and in relation tothe area of said relatively large cross-section is smaller than thedesired ratio of the liquid of lesser volume to the liquid of greatervolume, which method comprises flowing one of the liquids first throughsaid portion of relatively large cross-section at comparatively lowvelocity and high pressure and 10 cross-section.

then through said portion or reduced cross-section at higher velooitsand lower pressure. introducing the other of said liquids into saidconduit at said portion of reduced cross-section, and varying thepressure of said other liquid adjacent its point of introduction tosubstantially coincide with the pressure Of said one of the liquids insaid portion of relatively large crosssection in advance of said portionof reduced LEWIS G. MORRIS TI'MPSON.

